The present invention relates to the making of sterile connections between fluid conduit tubes and, more particularly, to a method and apparatus for joining in a sterile manner two disassociated fluid conduit tubes so as to enable fluid communication of sterile fluids therebetween.
There are many situations in the medical, scientific and biological arts where it is necessary to effectuate in systems the sterile transfer of fluids from one container to another, one apparatus to another, and the like. Generally speaking, the containers, apparatus, fluid conduit tubes and the like can be sterilized en masse for initial use so as to insure a microorganism-free environment, but innumerable situations arise where it is necessary to invade the sterile environment so as, for example, to add additional apparatus, remove samples, or the like. While the so-altered unit or system can perhaps be resterilized in toto before being placed back in use, this is an unsatisfactory approach in terms of time, convenience and economics.
Exemplary situations where these problems are encountered include supplying of blood or other essential fluids to a patient where it may be necessary to invade an initially sterile system so as to remove a depleted container of fluid and bring on stream a new supply of fluid. In such fields, the art has devoted considerable attention to the provision of means for effecting the sterile connections needed for adding or deleting components in the system. Some of the many patents in this area include U.S. Pat. No. 3,986,508 assigned to Abcor, Inc.; U.S. Pat. No. 4,475,900 to Popovich, et al.; U.S. Pat. No. 4,668,217 to Isono; U.S. Pat. Nos. 4,004,586, 4,242,310, 4,340,097, 4,473,369, and PCT Publications WO 84/02324, WO 83/02060 and WO 82/02528, all assigned to Baxter-Travenol Laboratories; and U.S. Pat. Nos. 4,369,779, 4,412,835, 4,443,215, 4,516,971, 4,507,119, 4,610,670 and 4,619,642, all assigned to E. I. duPont de Nemours & Co. In large part, these teachings involve relatively intricate connecting systems, melting of thermoplastic tube ends, and other like techniques.
Although given little attention in the art, another field where provision of sterile connections is of considerable importance is the in vitro culture of animal cells, a field of increasing importance for the production and recovery of cell-secreted proteins for therapeutic and/or diagnostic use. Since the culturing animal cells in such systems are arranged to grow and subdivide and produce product as if they were in an in vivo environment but are without the elaborate immune defense system which normally exists in that in vivo environment, the need for sterile culture conditions is quite apparent. In typical practice, the culture unit and its associated components (e.g., fluid conduit tubes for providing fresh medium and for withdrawing spent medium, oxygenation means, and the like) are provided in pre-sterilized format. However, the occasions are many where this sterile system must be invaded, either to cut in or delete culture medium containers, provide for cell and/or culture fluid analyses, add or delete culture chambers, and the like. Operation in a manner which requires that the system be resterilized in toto for each such invasion adds enormously to the complexity and cost of the culture operation. So too, reliance upon complex sterile connection schemes adds to the cost of operation and may result in yet further costs associated with the personnel required in order to correctly perform the needed operations.
In view of the foregoing, the primary object of the present invention is to provide a method and apparatus for quickly, simply and inexpensively effecting sterile connection between two disassociated fluid conduit tubes, whether they be tubes associated with containers or other apparatus, so that there can be established or reestablished a flow of sterile fluid through the connected tubing.
A more particular object of the invention is to provide a method and apparatus for interrupting a sterile fluid flow path through conduit tubing, e.g., by cutting through the tubing, and then effecting sterile connection between at least one of the resulting tube segments and another tube segment so as to reestablish a sterile flow of fluid through the newly-connected tubes. A still further object in this regard is to provide a method for this purpose which affords significant flexibility to the technician with respect to where along such tubing the interruption and connection can be effected.